// 
// Copyright (c) 2004-2006 Jaroslaw Kowalski <jaak@jkowalski.net>
// 
// All rights reserved.
// 
// Redistribution and use in source and binary forms, with or without 
// modification, are permitted provided that the following conditions 
// are met:
// 
// * Redistributions of source code must retain the above copyright notice, 
//   this list of conditions and the following disclaimer. 
// 
// * Redistributions in binary form must reproduce the above copyright notice,
//   this list of conditions and the following disclaimer in the documentation
//   and/or other materials provided with the distribution. 
// 
// * Neither the name of Jaroslaw Kowalski nor the names of its 
//   contributors may be used to endorse or promote products derived from this
//   software without specific prior written permission. 
// 
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 
// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE 
// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 
// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 
// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 
// CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 
// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF 
// THE POSSIBILITY OF SUCH DAMAGE.
// 

using System;
using System.Text;
using System.Globalization;

namespace NLog.LayoutRenderers
{
    /// <summary>
    /// The date and time in a long, sortable format yyyy-MM-dd HH:mm:ss.mmm
    /// </summary>
    [LayoutRenderer("longdate",UsingLogEventInfo=true)]
    public class LongDateLayoutRenderer: LayoutRenderer
    {
        /// <summary>
        /// Returns the estimated number of characters that are needed to
        /// hold the rendered value for the specified logging event.
        /// </summary>
        /// <param name="logEvent">Logging event information.</param>
        /// <returns>The number of characters.</returns>
        /// <remarks>
        /// If the exact number is not known or
        /// expensive to calculate this function should return a rough estimate
        /// that's big enough in most cases, but not too big, in order to conserve memory.
        /// </remarks>
        protected internal override int GetEstimatedBufferSize(LogEventInfo logEvent)
        {
            return 24;
        }

        private void Append2DigitsZeroPadded(StringBuilder builder, int number)
        {
            builder.Append((char)((number / 10) + '0'));
            builder.Append((char)((number % 10) + '0'));
        }

        private void Append4DigitsZeroPadded(StringBuilder builder, int number)
        {
            builder.Append((char)((number / 1000 % 10) + '0'));
            builder.Append((char)((number / 100 % 10) + '0'));
            builder.Append((char)((number / 10 % 10) + '0'));
            builder.Append((char)((number / 1 % 10) + '0'));
        }

        /// <summary>
        /// Renders the date in the long format (yyyy-MM-dd HH:mm:ss.mmm) and appends it to the specified <see cref="StringBuilder" />.
        /// </summary>
        /// <param name="builder">The <see cref="StringBuilder"/> to append the rendered data to.</param>
        /// <param name="logEvent">Logging event.</param>
        protected internal override void Append(StringBuilder builder, LogEventInfo logEvent)
        {
            if (NeedPadding())
            {
                builder.Append(ApplyPadding(logEvent.TimeStamp.ToString("yyyy-MM-dd HH:mm:ss.ffff", CultureInfo)));
            }
            else
            {
                DateTime dt = logEvent.TimeStamp;

                builder.Append(dt.Year);
                builder.Append('-');
                Append2DigitsZeroPadded(builder, dt.Month);
                builder.Append('-');
                Append2DigitsZeroPadded(builder, dt.Day);
                builder.Append(' ');
                Append2DigitsZeroPadded(builder, dt.Hour);
                builder.Append(':');
                Append2DigitsZeroPadded(builder, dt.Minute);
                builder.Append(':');
                Append2DigitsZeroPadded(builder, dt.Second);
                builder.Append('.');
                Append4DigitsZeroPadded(builder, (int)(dt.Ticks % 10000000) / 1000);
            }
        }
    }
}
